LIPS III solar array experiment using high emissivity coated coverslides

The design, construction, and experimental results of coupons flown on the US Naval Research Laboratory´s LIPS III mission are summarized. The main experiment is a comparison of performance in orbit of solar cells covered by standard coverslide material and those covered by coverslides coated with high-emissivity fused silica or CMS coatings. Preliminary optical measurements of the coatings suggest that the emissivity can be increased by as much as 10% thus reducing the equilibrium temperature of the panel in sunlight and increasing the cell operating efficiency. High-emissivity CMS on thin silicon reduces temperature by over 9 degrees C, whereas high-emissivity fused silica on GaAs produces a reduction of only 2 degrees C. It is not known why the reduction in temperature for the latter is lower than predicted, although the accuracy of measurements of all data is at this time in doubt and may partially explain the inconsistency.